Sensing configurations for non-uniform neurostimulation patterns

Abstract

A system may control when, with respect to a non-uniform waveform pattern used to deliver neurostimulation, to sense neural signals to appropriately control neurostimulation. The system may include a neural sensor configured to sense a neural signal, a neurostimulator configured to access a non-uniform waveform pattern and deliver the neurostimulation corresponding to the non-uniform waveform pattern, and a controller. The controller may be configured to automatically assign, based on the non-uniform waveform pattern, at least one sensing window for the non-uniform waveform pattern, control the neural sensor to sense the neural signal during the sensing window when the neurostimulation is delivered, and control the delivery of the neurostimulation from the neurostimulator based on the sensed neural signal.

What is claimed is: 
     
         1 . A method, comprising:
 accessing a non-uniform waveform pattern for use to deliver neurostimulation;   automatically assigning, based on the non-uniform waveform pattern, at least one sensing window for the non-uniform waveform pattern;   delivering neurostimulation corresponding the non-uniform waveform pattern;   sensing a neural signal during the at least one sensing window when the neurostimulation is being delivered; and   controlling delivery of the neurostimulation based on the sensed neural signal.   
     
     
         2 . The method of  claim 1 , wherein the non-uniform waveform pattern includes activation pulses that cause a neural response and sub-activation threshold pulses that do not cause the neural response, and the automatically assigning the at least one sensing window includes determining at least one pulse in the non-uniform waveform pattern that corresponds to the neural response and assigning the at least one sensing window to sense the neural response. 
     
     
         3 . The method of  claim 2 , wherein the determining the at least one pulse in the non-uniform waveform pattern includes using a relationship between a neural activation and at least one pulse parameter for the at least one pulse to determine the at least one pulse in the non-uniform waveform pattern that corresponds to the neural response. 
     
     
         4 . The method of  claim 3 , wherein the relationship is between the neural activation and at least one of a pulse amplitude, a pulse frequency or a pulse width. 
     
     
         5 . The method of  claim 2 , wherein the determining the at least one pulse in the non-uniform waveform pattern includes automatically determining a largest pulse amplitude in the non-uniform waveform pattern, and the at least one sensing window is automatically assigned to sense a neural response to the neurostimulation corresponding to the largest pulse amplitude in the non-uniform waveform pattern. 
     
     
         6 . The method of  claim 2 , wherein the determining the at least one pulse in the non-uniform waveform pattern includes automatically selecting multiple pulses in the non-uniform waveform pattern, and the at least one sensing window is assigned to sense a neural response to the neurostimulation corresponding to the automatically selected multiple pulses. 
     
     
         7 . The method of  claim 6 , wherein:
 the non-uniform waveform pattern is repeated to provide multiple instances of each pulse in the non-uniform waveform pattern;   the neurostimulation is delivered corresponding the repeated non-uniform waveform pattern; and   the sensing the neural signal includes sensing at least a first neural response to neurostimulation corresponding to a first selected pulse in the repeated non-uniform waveform pattern,   the method further comprising averaging the first neural response to neurostimulation corresponding to at least two instances of the first selected pulse in the repeated non-uniform waveform pattern.   
     
     
         8 . The method of  claim 7 , wherein the averaging the first neural response includes determining a weighted average of the first neural response corresponding to the at least two instances. 
     
     
         9 . The method of  claim 6 , wherein:
 the sensing the neural signal includes sensing at least a first neural response to neurostimulation corresponding to a first selected pulse in the non-uniform waveform pattern and a second neural response to neurostimulation corresponding to a second selected pulse in the non-uniform waveform pattern,   the method further comprising determining a weighted average of the first and second neural responses and controlling the delivery of the neurostimulation based on the weighted average.   
     
     
         10 . The method of  claim 1 , wherein the controlling the delivery of the neurostimulation based on the sensed neural signal includes modulating a mean for at least one pulse parameter based on the sensed neural signal. 
     
     
         11 . The method of  claim 1 , wherein:
 the non-uniform waveform pattern has a variable pulse parameter with parameter values within a parameter range that includes a minimum parameter value and a maximum parameter value within the parameter range;   the at least one sensing window is automatically assigned to sense a first extrema neural response to the neurostimulation corresponding to the minimum parameter value and a second extrema neural response to the neurostimulation corresponding to the maximum parameter value, and   the method includes:
 determining a desired neural response for the automatically assigned at least one sensing window based on the first and second extrema neural responses, and 
 using a deviation between the sensed neural response and the desired neural response to control the delivery of the neurostimulation. 
   
     
     
         12 . The method of  claim 11 , wherein the controlling the delivery of the neurostimulation based on the deviation includes modulating at least one of a center, depth or period for the variable pulse parameter to provide the desired neural response. 
     
     
         13 . The method of  claim 1 , further comprising:
 sweeping neurostimulation through a plurality of parameter values to collect threshold neural response data at one or more threshold parameter values;   designating threshold level specifications for the non-uniform waveform pattern based on the one or more threshold parameter values and the collected threshold neural response data; and   maintaining the neurostimulation within the threshold level specifications, using the collected threshold neural response data.   
     
     
         14 . The method of  claim 13 , wherein the sweeping the neurostimulation includes sweeping past a perception threshold parameter value, a maximum comfort threshold parameter value, or a discomfort threshold parameter value. 
     
     
         15 . The method of  claim 1 , further comprising identifying a meaningful epoch in the non-uniform waveform, wherein the at least one sensing window is automatically assigned during the identified meaningful epoch. 
     
     
         16 . The method of  claim 1 , further comprising identifying when an evoked potential or a local field potential change is expected, wherein the sensing window is automatically assigned during a quiescent period within the non-uniform waveform pattern when the evoked potential or the change in field potentials is expected. 
     
     
         17 . The method of  claim 1 , further comprising determining a quiescent period within the non-uniform waveform pattern that is longer than a threshold period of time, wherein the sensing window is automatically assigned to the quiescent period that is determined longer than the threshold, wherein the threshold period of time is a user-programmable period of time. 
     
     
         18 . The method of  claim 1 , wherein:
 the automatically assigning includes automatically assigning a first sensing window in a first non-uniform waveform pattern and automatically assigning a second sensing window in a second non-uniform waveform pattern;   the delivering neurostimulation includes delivering first neurostimulation corresponding to a first non-uniform waveform pattern at a first stimulation site and delivering second neurostimulation corresponding to a second non-uniform waveform pattern at a second stimulation site;   the sensing the neural signal includes sensing a first neural response to the first neurostimulation within the first sensing window and sensing a second neural response to the second neurostimulation within the second sensing window;   the controlling includes controlling delivery of at least one of the first neurostimulation or the second neurostimulation based on both of the first neural response and the second neural response.   
     
     
         19 . A non-transitory machine-readable medium including instructions, which when executed by a machine, cause the machine to perform a method comprising:
 accessing a non-uniform waveform pattern for use to deliver neurostimulation;   automatically assigning, based on the non-uniform waveform pattern, at least one sensing window for the non-uniform waveform pattern;   delivering neurostimulation corresponding the non-uniform waveform pattern;   sensing a neural signal during the at least one sensing window when the neurostimulation is being delivered; and   controlling delivery of the neurostimulation based on the sensed neural signal.   
     
     
         20 . A system, comprising:
 a neural sensor configured to sense a neural signal;   a neurostimulator configured to access a non-uniform waveform pattern and deliver the neurostimulation corresponding to the non-uniform waveform pattern; and   a controller configured to automatically assign, based on the non-uniform waveform pattern, at least one sensing window for the non-uniform waveform pattern, control the neural sensor to sense the neural signal during the at least one sensing window when the neurostimulation is delivered, and control delivery of the neurostimulation from the neurostimulator based on the sensed neural signal.